1. Field of the Invention
The present invention relates to method and system for managing accounting information in a mobile switching center (MSC). More particularly, the present invention relates to method and system for managing accounting information in an MSC configured to prevent abnormal termination of calls in progress and loss of accounting information due to the abnormal termination of the calls, when a system start-up request from an operator terminal occurs in an MSC, processing a lot of calls and operating the calls, due to software exchange, etc.
2. Description of the Related Art
As illustrated in FIG. 1, the mobile switching system includes subscriber call processing processors 1, trunk matching processors 2, a call process centralizing processor 3, visitor location register (VLR) processing processors 4 and an operation and maintenance processor (OMP) 5.
The subscriber call processing processor 1 and the trunk matching processor 2 are principal processors performing call processing functions and perform call connecting functions by cooperating with the call process centralizing processor 3 and the VLR processing processor 4. When the subscriber call processing processor 1 and the trunk matching processor 2 receive call termination requests for calls in progress from the OMP 5, the subscriber call processing processor 1 and the trunk matching processor 2 generate accounting information, transfer the accounting information to the OMP 5, release resources and terminate the calls.
The call process centralizing processor 3 performs common call processing functions, such as number translation, s-switch connection and disconnection, etc., regardless of subscriber call process performed by the subscriber call processing processor 1, trunk matching performed by the trunk matching processor 2, etc.
The VLR processing processor 4 requests subscriber location register information of subscribers in a certain area and the subscriber information by cooperating with a home location register (HLR) not included in a mobile switching system and temporarily stores the subscriber location register information and the subscriber information that received from the HLR.
The OMP 5 performs certain operations and maintenance in mobile switching system, system start-up/condition management, etc., receives accounting information transferred from the subscriber call processing processor 1 and the trunk matching processor 2, stores the accounting information in hard disk 6 and controls whether to extract the accounting information stored in the hard disk 6.
When operator requests restart-up of the mobile switching system for reasons of software exchange, etc., an operator terminal transfers the restart-up command to the OMP 5. The OMP 5 completes the restart-up of the OMP 5 and controls the other processors (the subscriber call processing processor 1, the trunk matching processor 2, the call process centralizing processor 3, the VLR processing processor 4, etc.) to perform restart-up of the processors themselves. For restart-up of the processors, software blocks such as processor loader (PL), system start-up loader (SSL), etc. performing restart-up of each processor exist in the processors.
The PL receives application software blocks to be operated from the hard disk 6 in turn and is loaded in the other processors except the OMP 5.
The SSL receives an application software block request from PL loaded in the other processors and is loaded in the OMP 5 by receiving the application software blocks in turn from the hard disk 6.
Hereinafter, a related art method of managing accounting information in a mobile switching center when restarting up the system will be described.
Let's assume that operator may command restart-up of the whole system in the present invention, even though operator may command both restart-up of the whole system and restart-up of certain software block.
An OMP 5 that received a restart-up command from an operator terminal generates a call termination message and commands each processor to terminate all operations in progress by transferring the call termination message to each processor. Each processor terminates all operations in progress after receiving the call termination message from the OMP 5. And, operating system performs restart-up by using a booter. When restart-up is completed, PL is loaded in each processor and, at the same time, the SSL is loaded in the OMP 5.
In other words, when the system is restarted up, PL is loaded in each processor by receiving application software blocks from the hard disk 6 in turn and SSL is loaded in the OMP 5 by receiving application software blocks from the hard disk 6 in turn.
Since the OMP 5 is directly connected to the hard disk 6 and the other processors are connected to the hard disk 6 through the OMP 5, restart-up of the system by the booter may be performed after the SSL is loaded in the OMP 5 by restart-up of the OMP 5.
In other words, when a restart-up request occurs, each processor terminates all operations in progress, tries a restart-up procedure by the booter, receives software blocks by transferring a certain message to SSL of the OMP 5 and loads PL in each processor.
Mobile switching system continuously proceeds with a lot of call outgoing/incoming trials, allotment and release of resources for supporting call connection states, request/response/renewal of related information, etc.
If restart-up command due to the necessity of software exchange is inputted from the operator during the continuous operations of the mobile switching system, the mobile switching system instantly shifts to an initial state with disregarding state of call process in progress. Accordingly, currently progressed calls in various states are abnormally completed and resources are lost.
There is a problem in that all records about calls are lost by the abnormal termination, though the records are important information, not only bases of accounting information for carrier's profit but also bases of civil appeals.